CVE-2020-1064 in Internet Explorer
Summary
by MITRE
A remote code execution vulnerability exists in the way that the MSHTML engine improperly validates input.An attacker could execute arbitrary code in the context of the current user, aka 'MSHTML Engine Remote Code Execution Vulnerability'.
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Analysis
by VulDB Data Team • 10/16/2020
The CVE-2020-1064 vulnerability represents a critical remote code execution flaw within Microsoft's MSHTML engine, which forms the core rendering component for Internet Explorer and other Microsoft applications. This vulnerability stems from inadequate input validation mechanisms within the engine's processing of HTML content, creating a pathway for malicious actors to inject and execute arbitrary code on affected systems. The flaw specifically manifests when the MSHTML engine encounters malformed or specially crafted HTML input, failing to properly sanitize or validate the content before processing. The vulnerability affects multiple Microsoft products including Internet Explorer, Microsoft Edge, and various Microsoft Office applications that utilize the MSHTML rendering engine. The security implications are severe as this vulnerability allows attackers to execute code with the privileges of the current user, potentially leading to complete system compromise and lateral movement within network environments.
The technical exploitation of this vulnerability occurs through the manipulation of HTML elements and attributes that the MSHTML engine processes without proper validation. Attackers can craft malicious web pages or documents containing specially constructed HTML code that triggers the vulnerable code path within the engine. The flaw typically involves memory corruption issues that arise during the parsing and rendering of malformed HTML structures, allowing attackers to overwrite memory locations and redirect execution flow. This type of vulnerability falls under CWE-121, which describes heap-based buffer overflow conditions, and is closely related to CWE-787, representing out-of-bounds write vulnerabilities. The attack vector requires user interaction through visiting malicious websites or opening compromised Office documents, making it particularly dangerous in phishing campaigns and targeted attacks. The vulnerability's exploitation can be automated through techniques such as JavaScript injection, ActiveX control manipulation, or memory corruption exploitation methods that have been documented in various threat actor toolkits.
The operational impact of CVE-2020-1064 extends beyond simple remote code execution, as it enables attackers to establish persistent access, escalate privileges, and conduct further reconnaissance within compromised environments. When successfully exploited, the vulnerability allows attackers to bypass security controls such as Data Execution Prevention (DEP) and Address Space Layout Randomization (ASLR) through sophisticated exploitation techniques. The vulnerability affects a broad range of Microsoft products including Internet Explorer versions 11, Microsoft Edge, and various Office applications, making it particularly dangerous for enterprise environments where these products are widely deployed. Organizations running affected versions of Microsoft products face significant risk of data breaches, system compromise, and potential lateral movement attacks. The vulnerability's presence in widely used software components means that exploitation can occur across multiple attack surfaces, including web browsing, document processing, and email client interactions. This makes the vulnerability particularly attractive to threat actors who can leverage it in mass exploitation campaigns targeting specific industries or organizations.
Microsoft addressed this vulnerability through security updates released as part of their regular patching cycle, including patches for Internet Explorer, Microsoft Edge, and Office applications. Organizations should prioritize immediate deployment of these security updates to protect against exploitation attempts. Additional mitigations include implementing browser security features such as Enhanced Protected Mode, disabling ActiveX controls, and employing application whitelisting solutions to prevent execution of unauthorized code. Network-based defenses such as intrusion detection systems can help detect exploitation attempts by monitoring for known malicious patterns in web traffic. The vulnerability demonstrates the importance of proper input validation and sanitization in software development, aligning with ATT&CK technique T1059.007 for command and scripting interpreter usage. Security teams should implement comprehensive monitoring for exploitation attempts and maintain updated threat intelligence feeds to identify emerging exploitation patterns targeting this vulnerability. Regular security assessments and penetration testing should include evaluation of MSHTML engine vulnerabilities to ensure proper patch management and configuration hardening measures are in place across all affected systems.